1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14
10// <optional>
11
12// constexpr T& optional<T>::value() &&;
13
14#include <optional>
15#include <type_traits>
16#include <cassert>
17
18#include "test_macros.h"
19
20using std::optional;
21using std::bad_optional_access;
22
23struct X
24{
25 X() = default;
26 X(const X&) = delete;
27 constexpr int test() const & {return 3;}
28 int test() & {return 4;}
29 constexpr int test() const && {return 5;}
30 int test() && {return 6;}
31};
32
33struct Y
34{
35 constexpr int test() && {return 7;}
36};
37
38constexpr int
39test()
40{
41 optional<Y> opt{Y{}};
42 return std::move(opt).value().test();
43}
44
45int main(int, char**)
46{
47 {
48 optional<X> opt; ((void)opt);
49 ASSERT_NOT_NOEXCEPT(std::move(opt).value());
50 ASSERT_SAME_TYPE(decltype(std::move(opt).value()), X&&);
51 }
52 {
53 optional<X> opt;
54 opt.emplace();
55 assert(std::move(opt).value().test() == 6);
56 }
57#ifndef TEST_HAS_NO_EXCEPTIONS
58 {
59 optional<X> opt;
60 try
61 {
62 (void)std::move(opt).value();
63 assert(false);
64 }
65 catch (const bad_optional_access&)
66 {
67 }
68 }
69#endif
70 static_assert(test() == 7, "");
71
72 return 0;
73}
74

source code of libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_rvalue.pass.cpp